The present invention relates to a ratchetable adjustable wrench which is adapted to engage a variety of non-circular fasteners, and in particular hex nuts and hex bolt heads, and which has a fastener engaging head which is selectably ratchetable.
Non-ratcheting adjustable wrenches of the general type with which the present invention is concerned are well known. Examples of such adjustable wrenches are shown, for example, in U.S. Pat. No. 2,912,891, issued Nov. 17, 1959, to T. Neff, U.S. Pat. No. 3,204,497, issued Sep. 7, 1965, to L. R. Dinkler, U.S. Pat. No. 4,520,699, issued Jun. 4, 1985, to M. Jeremic, U.S. Pat. No. 4,967,613, issued Nov. 6, 1990 to R. E. Cone, and U.S. Pat. No. 5,415,064, issued May 16, 1995 to C-H. Chang.
The standard arrangement for such adjustable wrenches is to have two jaws, one fixed with respect to the wrench handle and the other movable with respect to the fixed jaw. Typically, as is illustrated in the aforesaid patents, the movable jaw has an actuator element onto which an external male thread is formed, the movable jaw being attached to the actuator element by any one of a variety of means. The handle includes a knurled knob which has a complementary female threaded aperture extending therethrough, through which the male threaded actuator element extends so as to engage the female threads. Manual rotation of the knob, as by a user's thumb, causes the rotary motion of the knob to be translated into linear motion of the movable jaw, so as to selectively either clamp the jaws on to the element to which torque is to be applied or to loosen the jaws therefrom.
These prior art adjustable wrenches all suffer from a lessened degree of utility, because when they are engaged to apply torque to a fastener, either to tighten it or to release it, the adjustable wrench must be periodically removed from and reapplied to the fastener as rotation of the wrench moves the wrench against a physical stop caused by nearby structure.
Non-adjustable ratcheting wrenches are well known in the prior art. They fall generally into two classes, box end wrenches with an external ratcheting mechanism for the box, such as is shown in U.S. Pat. No. 4,748,875, issued Jun. 7, 1988 to John W. Lang, for example, and open end wrenches utilizing unique fastener gripping surfaces, such as is shown in U.S. Pat. No. 4,889,020, issued Dec. 26, 1989 to David R. Baker, for example. However such prior art non-adjustable ratcheting wrenches suffer from a common lessened degree of utility in that a given wrench may only be utilized with a single size of fastener, necessitating the availability of a multiplicity of wrench sizes to insure availability of the ratcheting function.
Consequently, a need exists for an ratcheting adjustable wrench which will be strong, easy to use, can be used in close quarters, and can fully grip the object to which torque is to be applied while avoiding the design deficiencies inherent in the prior art structures of adjustable wrenches and ratcheting wrenches referred to above.